hedgesteeper
New Member
Have been given a Stihl MS170 as a non runner. Stripped and cleaned carb and it now fires easily and runs up okay except for excessive smoke which smells like the crankcase is ingesting bar oil somehow. Is this possible?.
Stihl MS170 acrid smoke
- Thread starter hedgesteeper
- Start date
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If it was really badly flooded it may just have a lot of residual oil left in the crankcase.
On a lot of saws it is possible for the join in the case to fail between the oil tank & the crankcase
On a lot of saws it is possible for the join in the case to fail between the oil tank & the crankcase
hedgesteeper
New Member
It runs okay, it's just that the oil is acrid smelling which suggests, from reading other threads, that bar oil may be ingesting from a failed o ring on the bar oil pump, perhaps.
The ms170 has a separate oil tank from the case. Just empty the oil and see if the condition improves
Did you flush the fuel system? Maybe the muffler is full of some kind of solvent? Did you check the screen?
hedgesteeper
New Member
It ran up perfectly after I serviced it but then after filling up the bar oil reservoir it's burning acrid smoke. Will empty the bar oil tank to verify the idea that it's leaking either onto the exhaust or into the crankcase by some means.
I just finished a complete teardown/rebuild on a 170. There is a hose that runs from rear lower oil tank, underneath the saw, up to the oil pump. Unless it's being sucked in through the seal on the clutch side, I can't envision any way bar oil could be getting into the crankcase, especially since it's a clamshell motor.
NHden
ArboristSite Member
Is it possible that you're smelling the plastic surrounding the clutch burning? If the clutch were slipping, the drum and clutch get very hot very fast. See if the drum and sprocket are discolored. If they are, clean and inspect the drum and clutch. If the clutch shoes were sticking from rust, corrosion or gunk, they might not apply enough outward force on the drum.
